Calculation method of spherically expanding flame propagation radius to consider ignition electrode effects

Ignition electrodes have an immense impact on the accurate measurement of the flame propagation spherical radius. In this study, a flame-radius calculation method is designed. The method is able to eliminate effects due to the ignition electrodes. The adaptability and optimization effects of the proposed method are analyzed. The results show that the ratio of the angle is affected by the ignition electrodes under the Han II method. There are three obvious divisions include a high-value area, a sharp-variation area, and a mild-variation area. The ratio of the angle affected by the ignition electrodes is only applicable to the mild-variation region when the flame presents respective convex and concave distributions. For these distributions, the increment rate of the mean radius is 0.4-0.85% and 0.42-3.19%. The reduced rate of the standard deviation of the radius extraction value is 11.91-22.1% and 5.13-17.99%, and the reduced rate of the radius extraction value range is 20.32-39.51% and 0.32-8.09%.

Assessment of the potential for phytoremediation of cadmium polluted soils by various crop rotation patterns based on the annual input and output fluxes

Phytoremediation potential of two oil crop rotations (oilseed sunflower-rape (O+Ra) and peanut-oilseed rape (P+Ra)) was compared with three conventional cropping patterns (rice-rape (R+Ra), rice-rice (R+R), single cropped rice (SR)) in experimental plots with cadmium (Cd)-contaminated soil. A new approach was used to evaluate phytoremediation potential based on the balance between annual input and output fluxes of Cd in farmland soil. In O+Ra and P+Ra rotations, 77.24 and 62.09 g/ha Cd were removed, respectively, whereas in R+Ra, R+R, and SR patterns, 41.79, 46.46, and 23.85 g/ha Cd were removed, respectively. The balance between inputs and outputs of Cd was - 40.72 and - 25.76 g/ha under O+Ra and P+Ra rotations, respectively. Available Cd content in topsoil was reduced by 5.58% and 3.91% under O+Ra and P+Ra rotations, respectively. Based on the balance between Cd inputs and outputs, phytoremediation efficiencies of O+Ra (1.23%) and P+Ra (0.78%) rotations were higher than those of R+R (0.29%), R+Ra (0.13%), and SR (-0.38%) systems. Because crop removal is the main Cd output pathway, selection of a suitable crop is particularly important in remediation of Cd-contaminated farmland.

Blue, green, and grey water footprints assessment for paddy irrigation-drainage system

Water footprint (WF) quantifies the impact of paddy field evapotranspiration (ET) and non-point source pollution on water resources and is an evaluation index for water sustainability. However, it is difficult to measure accurately using the existing method, which is based on parameter assumption without considering the field water conditions. In this study, a generic and physically based method for blue, green, and grey water accounting in paddy rice cultivation is introduced. We conducted field experiments using the common flood irrigation (CFI) and water-saving irrigation (SWI) modes in Nanjing, East China. By tracing the sources of ET and the migration process of multiple pollutants (TN, TP, NH₄⁺-N, and NO₃^--N), the characteristics of blue-green water consumption and the actual amount of water required to dilute pollutants at different growth stages of rice under CFI and SWI were analyzed. The WF of paddy rice was 1000 m³/t (49% WF_green, 17% WF_blue, 34% WF_grey) and 910 m³/t (50% WF_green, 10% WF_blue, 40% WF_grey) for CFI and SWI, respectively. The WF for paddy rice production was reduced by approximately 9% under SWI compared to CFI, with declines of 47% for WF_blue and 8% for WF_green. The SWI mode changed the ratio of blue to green water fluxes in field water by reducing irrigation during non-critical periods, and green water was used preferentially to enhance its utility. This conceptual method is the first to describe the formation mechanism of blue, green, and grey WFs in paddy systems. It can be extended to different scales and agro-ecosystems that show the influence of crop cultivation on water resources.

Common clothing area factor estimation equations are inaccurate for highly insulating (Icl>2 clo) and non-western loose-fitting clothing ensembles

The aim of this study was to evaluate the equations for calculating the clothing area factor (f_cl) used in the standards based on data sets of clothing ensembles, that are meant to provide thermal comfort over a wide range of climatic conditions from hot summer days to extremely cold winter. Over 10 equations for f_cl calculations were selected from the international standards and the literature. At first a theoretical comparison based on a range of insulation values was performed. Then the data sets were used to compare the equations and measurements on real clothing systems. Most of the f_cl calculation equations do give reasonably good results for western type and industrial clothing with basic insulation (I_cl) up to 1.5 clo. Above the I_cl of 2 clo, the error in the calculations based on traditional equations increases considerably and they overestimate f_cl. Some new equations were suggested for modern clothing systems. Oppositely, for non-western clothing (for hot climate), the available equations did give good match only for very light clothing sets and commonly underestimated the real f_cl. For such sets and and fashion clothes their own equations maybe needed, that count for various design aspects, e.g. fit, draping etc.

Research on the Establishment and Application of the Environmental Health Indicator System of Atmospheric Pollution in China

To understand the health impact represented by exposure to current atmospheric pollution in China, an environmental health indicators (EHIs) system of atmospheric pollution was established. The EHIs were based on comprehensive consideration of environment, population, economy and diseases associated with atmospheric pollution. An EHIs evaluation system of atmospheric pollution, based on corresponding EHIs data collection and weighting coefficients determined using principal component analysis, was applied to major provinces and regions in China to evaluate the environmental health status. Results showed that the EHIs of atmospheric pollution in Central and East China were low, indicating a serious environmental health condition. Prevention and management of atmospheric pollution in these regions should be strengthened and protective measures taken to improve human health. Compared with other methods, the EHIs evaluation system was more intuitive, which facilitated users to identify the environmental health status and provided support for health management and pollution prevention.

[Calculation Method of Incubation Period of Infectious Diseases and Its Epidemiological Significance]

Based on the practical application, this paper introduced the basic calculation conditions, methods and epidemiological significance of incubation period. The real data were used for calculations of the incubation period by lognormal, gamma, Weibull and Erlang distribution methods. Both of the complete and incomplete observation data were demonstrated.

Calculation method to predict postoperative limb length in patients undergoing THA following developmental dysplasia of hips

BACKGROUND

Limb length discrepancy (LLD) is one of the main cause of dissatisfaction after total hip arthroplasty (THA). The teardrop-lesser trochanter method can accurately predict and analyze LLD for healthy people. However, for patients with preoperative LLD, no method for predicting postoperative LLD is currently available, and these patients are highly susceptible to more severe LLD after THA. Accordingly, this study proposed a calculation method to predict postoperative limb length for these patients.

METHODS

Eighty patients who underwent THA between May 2016 and October 2018 due to unilateral developmental dysplasia of the hip (DDH) were evaluated. Relevant parameters were measured from radiographs of full-length lower limbs, e.g. the distance between the rotation center of the hip and the midpoint of the tibial plafond and the distance between the point which was marked at the same height as the lesser trochanter on the anatomical long axis of the femur and the midpoint of the tibial plafond. Then, a mathematical model was established by simplifying the structure from the hip to the ankle. The relationship between the placement position of the prosthesis and the LLD value was calculated by Law of Sines and Iterative Calculation.

RESULTS

The preoperatively predicted LLD values and the postoperatively measured LLD values were compared, yielding a mean absolute difference of 3.7 (range, 0.1 to 8.6) mm. The intraclass correlation coefficient (ICC) of the two parameters exhibited strong reliability (ICC = 0.911, 95%CI, 0.795 to 0.955). The Bland-Altman plot also showed good conformity between the two parameters.

CONCLUSIONS

The proposed calculation method effectively predicted the postoperative LLD using preoperative parameters. Despite the complexity of the method, it can go a long way towards reducing the occurrence of severe postoperative LLD in DDH-THA.

An improved method for estimating GHG emissions from onshore oil and gas exploration and development in China

Greenhouse gas (GHG) emissions from oil and gas exploration and development are major contributors to emission inventories in oil and natural gas (ONG) systems. For the developing countries, including China, studies of this aspect of the industry, being at an early stage, lack a unified method of calculation, and this leads to varied projections of national emissions. In this paper, progress is reported on direct measurement of CH₄ and CO₂ emissions along the oil and gas value chain, for four oil and gas fields. An improved calculation method (classification calculation method), which considers the production status of each type of oil and gas field in China, is proposed for the first time in this study. Based on in situ measurement, it is used to estimate the national CH₄ and CO₂ emissions from the process of petroleum exploration and development. The results showed that CH₄ and CO₂ emissions in 2013 were 73.29×10⁴ and 20.32×10⁴tonnes, respectively (in CO₂ equivalent: 1559.36×10⁴tonnes). Compared with the results (731.52×10⁴tonnes of CH₄, 1031.55×10⁴tonnes of CO₂, 16,393.48×10⁴tonnes of CO₂ equivalent) in 2013 determined by the Tier 1 method of the Intergovernmental Panel on Climate Change (IPCC), the carbon emissions from field measurement method were much lower than that of IPCC method, which indicated that carbon emissions of ONG systems in China were severely overrated by IPCC. Hence, the GHG emission results reported herein could fundamentally improve the knowledge and understanding of GHG emissions from ONG exploration and development in China.